1. Field of the Invention
The present invention relates to an imaging unit which includes an imaging optical system and an image sensor. The present invention also relates to a mobile electronic device which includes the imaging unit.
2. Description of the Related Art
In recent years, various mobile electronic devices which are designed either for taking still/moving images or to have the capability of taking such images as a subsidiary function, such as digital cameras (still-video cameras), digital camcorders (motion-video cameras), mobile phones with a camera, and personal digital assistants (PDAs), have become widespread, and it has been desired to slim down the on-board imaging device as part of improvements in portability of such mobile electronic devices. For instance, a type of imaging optical system in which an optical path is bent to slim down the imaging optical system by the use of two prisms which are installed on the incident side (that faces the subject (object)) and the exit side (that faces an image sensor), respectively, has been proposed. This type of imaging optical system is disclosed in Japanese unexamined patent publication 2006-154705.
This patent publication has merely proposed such a slimmed-down type of imaging optical system, thus not showing any specific structure of an imaging device which is designed to be installed in an electronic device.